Research in the Molecular Pathogenesis is focused on defining changes in the genes that underlie inherited susceptibilities to common diseases such as cancer and birth defects. Changes in folate metabolism are correlated tumor formation and birth defects. Folate genes are also involved in the methylation of DNA. We are searching for genetic variants in genes related to folate, methionine and homocysteine metabolism. Individuals affected with cancer or spina bifida will be tested for these variants. Variants found at higher frequency in individuals with disease will help us identify genes associated with risk. More than 30 variants in folate related genes have been identified. A portion of these have been tested in spina bifida families. Initial evidence suggests that two of these new variants are associated with spina bifida risk. We will test the function consequences of these variants in experimental systems. The frequency of the same variants will be measured in individuals with cancer. If confirmed, these two genes will add to our understanding of neural tube defects and cancer risk.